Note: Descriptions are shown in the official language in which they were submitted.
20068S9
2393R
TITLE: SULFUR-CONTAINING POLYMERIC POLYESTERS AND
ADDITIVE CONCENTRATES AND LUBRICATING OILS
CONTAINING SAME
FIELD OF THE INVENTION
This invention relates to lubricating compositions.
More particularly, this invention relates to
sulfur-containing polymeric polyesters, methods for
preparing them, additive concentrates and lubricating
compositions comprising sulfur-containing polymeric
polyesters. In a general sense, the polyesters are
derived from polybasic acids or anhydrides, particularly,
succinic acids or anhydrides.
BACKGROUND OF THE INVENTION
Numerous esters and polyesters are known. Many are
described as being useful as additives for lubricants and
fuels. Illustrative examples of patents containing such
disclosures include the following:
U.S. 2,540,570 teaches glycol or thioglycol esters of
fatty acids, rosin acids, tall oil acids, etc. which are
sulfurized or phosphorized. They are said to perform as
extreme pressure additives in lubricants.
Esters of di- and tribasic carboxylic acids, having
alkenyl substituents are prepared by esterifying the
corresponding acid with primary monohydric alcohols or
with monohydric alcohols containing oxygen or sulfur in
ether or thioether linkages. These monomeric compounds
2006859
are also taught as being suitable for use as lubricatina
oils.
U.S. 2,575,195 describes complex esters prepared by
reacting one mole of a dibasic acid with one mole of a
glycol in such a manner that a half ester is formed, after
which the terminal hydroxyl and carboxyl groups are
esterified with a monobasic acid and monohydric alcohol,
respectively.
U.S. Patent 2,575,196 teaches complex esters prepared
by reacting one molecular proportion of a monobasic
aliphatic acid with one molecular proportion of a glycol,
forming a half ester of the glycol, after which two
molecular proportions of such half ester are reacted with
one molecular proportion of a dibasic aliphatic acid. The
products of these patents are taught as being useful as
synthetic lubricants and for use with mineral lubricating
oils to give lubricants of improved viscosity index and
pour point.
In U.S. 2,610,202 a compound made by reacting maleic
anhydride with beta-mercaptoethanol is further reacted
with a normal primary alcohol.
U.S. 2,929,786 teaches polyesters prepared from
dibasic acids, or their esters, and glycols, including
glycols containing thioether linkages. These compositions
are said to be useful as additives or blending components
in synthetic lubricant compositions.
A wide variety of esters of alkenyl succinic acids
and anhydrides thereof are described as deposit modifiers
for substantially hydrocarbon fuels. The esters are of
mono-, di- and polyfunctional alcohols including
mercaptoalkanols. U.S. Patents 3,045,042 and 3,117,091
teach monomeric partial esters prepared by the reaction of
alkyl or alkenyl succinic anhydrides with diols, triols or
other polyhydric compounds including thiodiethanol.
Ester derivatives of hydrocarbon-substituted succinic
acids containing at least about 50 aliphatic carbon atoms
in the hydrocarbon substituent, which esters are prepared
20~i859
from monohydric and polyhydric alcohols, phenols and
naphthols, are useful as additives in lubricating
compositions, fuels, hydrocarbon oils and power
transmitting fluids as well as being plasticizers,
detergents, anti-rust agents and emulsifiers. Such
materials are described in U.S. 3,522,179.
Functional fluid compositions containing ester
additives derived from hydrocarbon substituted (which
substituents include substituted hydrocarbon, preferably
sulfur-substituted hydrocarbon) succinic acid and
thio-bisalkanols are described in U.S. 4,702,~50.
Each of the above-referenced patents is hereby
expressly incorporated herein by reference for relevant
disclosures contained therein.
SUMMARY OF THE INVENTION
This invention relates to a process for preparing a
sulfur-containing polymeric polyester which comprises
reacting at least one acid-ester of an alpha-beta
unsaturated polybasic acid or functional derivative
thereof, wherein said acid-ester contains an average of
from about 1 to about 1.3 carboxylic acid groups, with a
mixture of a source of sulfur and a mercaptoalkanol of the
formula
HS- (RO) nH (I)
wherein R is an alkylene group, and n is a number ranging
from 1 to about 20.
In a further embodiment, a composition of matter is
described comprising a sulfur-containing polymeric
polyester comprising at least 2 repeating units of the
formula
20068S9
o o
Il !l
Ra(OR)mO_C~ /C--O(RO)mRa
A S A (II)
- C C - (OR)nSx- (RO)n-
O
wherein each A is independently an alkylene group
containing from 2 to about 24 carbon atoms, each Ra is
independently H or an alkyl or aryl group, each R is
independently an alkylene group, each x is independently a
number from 1 to about 6, each m is independently 0 or a
number from 1 to about 20, and each n is a number ranging
from 1 to about 20.
In another embodiment, this invention relates to a
process for preparing a sulfur-containing polymeric
polyester which comprises reacting a sulfur-coupled
acid-ester of a polycarboxylic acid,
(RcC)dR3-sx-R3(cRc)d (X)
wherein R3 is a hydrocarbyl group, each Rc is
independently H, Ra(OR)m , wherein R, Ra and m are as
defined hereinabove, or hydrocarbyl, with the proviso that
at least one Rc in each (COORC)d group is H, and d is at
least 2, and wherein each (COORC)d group contains an
average of from 1 to about 1.3 carboxylic acid groups,
that is, groups where Rc is H, x is a number from 1 to
about 6, with at least one member of the group of
thiodialkanols of the formula
H(ORSxR)nOH ~ (IV)
the formula
2006859
( )n x ( )n (V)
and the formula
HO (RS) ROH (XI),
wherein x is a number from 1 to about 6, each R is
independently an alkylene group and each n is
independently a number from 1 to about 20.
In further embodiments, polymeric compositions
prepared by the processes of this invention and
lubricating oil compositions comprising these polymeric
compositions are described.
In still another embodiment, this invention relates
to lubricating oil compositions comprising a major amount
of an oil of lubricating viscosity and a minor amount of a
polymeric sulfur-containing polysuccinate ester having at
least 2 repeating units of formula
O O
¦ Q - (VI)
wherein each Q is independently
n y n (VII)
or
(ORSyR)nO (VIII),
each Rb is independently hydrocarbyl or hydrocarbylthio,
each R is independentlv an alkylene group, each y iS
independently 0 or a number ranging from about 1 to about
6, and n is a number ranging from 1 to about 20, with the
proviso that at least one Rb is hydrocarbylthio.
Thus, it is an object of this invention to provide
sulfur-containing polyesters.
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-- 6
Another object is to provide lubricating oil and
functional fluid compositions containing sulfur-containing
polyesters.
A further object is to provide effective lubricating oil
compositions containing reduced levels, often less than
0.08~, frequently less than 0.05~, by weight of phosphorus.
An additional object is to provide effective lubricating
oil compositions that are essentially free of phosphorus.
These and other objects, advantages and features of the
present invention will become apparent to those persons
skilled in the art upon reading the details as more fully set
forth below.
DETAILED DESCRIPTION OF THE INVENTION
Before the present sulfur-containing polyesters and
processes for making such are described, it is to be
understood that this invention is not limited to the
particular polymeric polyesters or processes described as
such compounds and methods may, of course, vary. It is also
to be understood that the terminology used herein is for the
purpose of describing particular embodiments only, and is not
intended to be limiting since the scope of the present
invention will be limited only by the appended claims.
It must be noted that as used in this specification and
the appended claims, the singular forms "a", "an" and "the"
include the plural unless the context clearly dictates
otherwise. Thus, for example, reference to "a
mercaptoalkanol" includes mixtures of mercaptoalkanols,
reference to "an acid-ester" includes mixtures of such acid-
esters, reference to "a polysuccinate ester" includes
mixtures of polysuccinate esters and so forth.
Several terms are used herein, which terms are
defined hereinbelow. The term "hydrocarbyl" is used
herein to include substantially hydrocarbyl groups (for
.,
Z006859
-- 7
example, substantially hydrocarbyloxy, etc.", as well as
purely hydrocarbyl groups. Such groups mav also be
described as "hydrocarbon" groups, and the words maY be
used interchangeably unless the context clearly dictates
otherwise. The description of groups as being
substantially hydrocarbyl means they contain no
non-hydrocarbyl substituents or non-carbon atoms which
significantly affect the hydrocarbyl characteristics or
properties of such groups relevant to their uses as
described herein. Substituents which do not significantly
alter the hydrocarbyl characteristics or properties of the
hydrocarbyl group containing components of this invention
will readily occur to those skilled in the art.
The term "hydrocarbyl" is not intended to infer any
particular structure or valence. Thus, for example, a
"hydrocarbyl" group may be alkyl, alkylene, aryl, aralkyl,
arylene, alkaryl, etc. The nature of particular
hydrocarbyl group referred to herein will be apparent to
one of ordinary skill in the art.
Examples of hydrocarbyl groups or substituents which
might be useful in connection with the present invention
include the following:
(1) hydrocarbon groups or substituents, that is
aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g.,
cycloalkyl, cycloalkenyl) substituents, aromatic,
aliphatic and alicyclic-substituted aromatic nuclei and
the like as well as cyclic substituents wherein the ring
is completed through another portion of the molecule (that
is, for example, any two indicated substituents may
together form an alicyclic radical);
(2) substituted hydrocarbon groups or substituents,
that is, those containing nonhydrocarbon substituents
which, in the context of this invention, do not alter the
predominantly hydrocarbon character of the substituted
group or substituent and which do not interfere with the
reaction of a component or do not adversely affect the
performance of a material when it is used in an
X006859
-- 8
application within the context of this invention; those
skilled in the art will be aware of such radicals (e.g.,
alkoxy, carbalkoxy, alkylthio, sulfoxy, etc.);
(3) hetero groups or substituents, that is, groups
or substituents which will, while having predominantly
hydrocarbvl character within the context of this
invention, contain atoms other than carbon present in a
ring or chain otherwise composed of carbon atoms.
Suitable heteroatoms will be apparent to those of ordinary
skill in the art and include, for example, sulfur,
oxygen, and nitrogen. Moieties such as, e.g., pyridyl,
furyl, thienyl, imidazolyl, etc., are exemplary of hetero
groups or substituents. No more than two heteroatoms, and
preferably no more than one, will be present for each ten
carbon atoms in the hydrocarbon-based groups or
substituents.
Typically, unless otherwise specified, the
hydrocarbon-based groups or substituents of this invention
are essentially free of atoms other than carbon and
hydrogen and are, therefore, purely hydrocarbyl.
Throughout the specification and claims of this
invention, polyesters are described as polymeric
polyesters. The expression "polyester" is often used in
the art to refer to materials containing a plurality of
ester groups. Thus, using such a definition, polyol
esters derived from a polyol and a monobasic acid, for
example, a triglyceride, or polycarboxylic acid esters
derived from a polycarboxylic acid and a monohydric
alcohol, for example, butyl succinate, could be considered
polyesters. While the polymeric polyesters of this
invention may comprise one or more such moieties,
materials which comprise such moieties, but which are not
polymeric polyesters, as defined herein are not part of
this invention. Polymeric polyesters contain ester groups
in repeating units described hereinabove, and hereinafter
and in the claims.
2006859
As mentioned hereinabove, one embodiment of this
invention relates to a process for preparing a
sulfur-containing polymeric polyester which process
comprises reacting, in the presence of a catalyst, at
least one acid-ester of an alpha-beta unsaturated
polybasic acid or funetional derivative thereof, wherein
said aeid-ester is described in detail hereinbelow, with a
mixture of a source of sulfur and a mercaptoalkanol of the
formula
HS-~RO~nH (I)
wherein the elements of mercaptoalkanol (I) are described
in detail hereinbelow.
The Acid-Ester
The acid-ester has the general formula
Ro(COORC)d (IX)
wherein Ro is a hydrocarbon group characterized by the
presence therein of an ethylenic linkage in an alpha-beta
position with respect to at least one (COORC) group. The
Ro group may contain from ~ to about 20 carbon atoms,
preferably 2 to about 8 carbon atoms, more preferably from
2 to about 4 carbon atoms. The Ro group may be
substituted by a hydrocarbon group of from 1 to about 24
carbon atoms; however, most often Ro does not contain such
substituents. Each Rc is independently hydrogen, Ra(OR)m,
wherein Ra, R and m are as defined hereinabove, or
hydrocarbyl, preferably alkyl, having from 3 to about 30
carbon atoms, often from about 4 to about 24 carbons, with
the proviso that at least one Rc is hydrogen, and the
(COORC)d group contains an average of from 1 to about 1.3
carboxylic acid groups (groups of the formula COOH). The
subscript d is a number ranging from two to about 8,
preferab]y 2 to about 3. Preferred acid-esters are
maleate or fumarate monoesters.
20068~9
- 10 -
Methods for preparing acid-esters useful in the process
of this invention are well known in the art. One
particularly useful method is to react about one mole of an
acidic reactant, for example, an anhydride such as maleic
anhydride, with about one mole of an alcohol, often in the
presence of a catalyst, for example, sodium acetate. Other
useful acidic reactants include, but are not limited to,
maleic acid, fumaric acid, itaconic acid, itaconic anhydride,
citraconic acid, citraconic anhydride, mesaconic acid,
glutaconic acid, aconitic acid, and the like. For reasons of
cost, availability and the like, the acid-esters are often
derived from an alpha-beta unsaturated dibasic acid or
functional derivative thereof, such as maleic acid or
anhydride. Useful alcohols for preparing the acid esters,
for the sake of cost, availability and ease of use are
primary monohydric alcohols. Exemplary alcohols include
lower alcohols such as methyl, butyl, hexyl, etc., alcohols,
fatty alcohols such as caprylic, oleic, etc., and
commercially available mixtures, for example, mixtures sold
under the name Neodol* (Shell).
The acid-ester may be pre-formed or may be formed i
situ. A pre-formed acid-ester reactant may be one which has
been manufactured separately. Also included as a pre-formed
acid-ester is one which is prepared just prior to use. In
the latter case, the reaction vessel used for the process of
this invention may also be used for preparing the acid-ester.
Following preparation of the acid-ester reactant, the
remaining reactants may be added as described hereinafter.
Often, it is not necessary to purify the acid-ester before
proceeding with the subsequent reaction.
When the acid-ester is formed ln situ, at least some of
the reactants to be used in the reaction to form products of
this invention may be present in the reaction mixture.
*Trade-mark
-
2006859
- 11 -
It is preferred to employ a pre-formed acid-ester. For
reasons of economics and processing flexibility, preparation
of the acid-ester just prior to use, as described above, is
particularly preferred.
Functional derivatives which react in a manner such that
polyesters of the same type as are prepared from the acid-
ester described hereinabove are also useful. Such functional
derivatives may include esters of lower alcohols, amides,
acyl halides and the like.
The Source of Sulfur
The source of sulfur useful in the process of this
invention usually is elemental sulfur, which may be present
as any of the allotropic solid forms or as molten sulfur.
Other useful sources of sulfur include a mixture of sulfur
dioxide and hydrogen sulfide which react yielding elemental
sulfur and water, organic polysulfides, hydrogen polysulfide
and the like. Other sources of sulfur will occur to those
skilled in the art. For reasons of cost, availability and
ease of use, elemental sulfur is preferred.
The amount of the source of sulfur which will be
employed in the process is that amount which will yield a
sulfur-containing polyester containing the desired amount of
sulfur. Amounts in excess of that needed to attain the
desired sulfur content in the sulfur-containing polyester
often result in products having undesirable properties such
as precipitation of sulfur, excessive sulfur activity, or are
simply wasteful of raw materials.
The source of sulfur is preferably used in amounts
adequate to provide from about 0.1 to about 4 moles of sulfur
per mole of the acid-ester. Preferably, from about 0.5 to
about 3 moles, more preferably from about 0.5 to about 1 mole
of sulfur per mole of acid-ester, is provided by the source
of sulfur. As mentioned hereinabove, the source of sulfur is
preferably elemental sulfur.
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- 12 -
The Catalyst
Catalysts are often useful in the process of this
invention. Optional catalysts include esterification
catalysts. A sulfurization catalyst appears to facilitate
the sulfurization reaction. The amount of sulfurization
catalyst, when used, varies, depending on the nature of the
catalyst. Usually at least about 0.01~ by weight of catalyst
is used, often from about 0.01 to about 5~, frequently from
about 0.1 to about 2~ or 0.1 to about 1~ by weight.
A preferred sulfurization catalyst is magnesium oxide.
The use of magnesium oxide as a catalyst for the
sulfurization of alkyl mercaptans is described in Canadian
patent 1,231,973. Other catalysts taught by this European
Patent Application to be useful are the remaining alkaline
earth metal oxides such as calcium oxide and barium oxide.
It is taught that in order for the alkaline earth metal
oxides to be effective catalysts, they must be used in
combination with alcohols, for example, isopropyl alcohol and
butyl alcohol. Numerous other sulfurization catalysts are
known, and are described in the literature. Many useful
catalysts are described in Davis, U.S. Patent 4,119,549 along
with Canadian Patent 1,231,973.
Various metal-containing compounds serve as catalysts
for esterification of a carboxylic acid moiety with an OH-
containing reagent. Particularly useful catalysts aretitanium alkoxides, tin carboxylates, aluminum alkoxides, and
certain metal-containing oxides including Sb2O3, SnO2 and PbO3.
Catalysts such as sulfuric acid, pyridine hydrochloride,
hydrochloric acid, benzene sulfonic acid, p-toluene sulfonic
acid, phosphoric acid, or any other known esterification
catalyst may be used. Other materials useful as catalysts
will occur to the skilled worker. The amount of the catalyst
in the esterification reaction may be as little as 0.01~ by
.~
20U~8~9
weight of the reaction mixture, more often from about 0.1~ to
about 5~.
The Mercaptoalkanol
The process for preparing a sulfur-containing polyester
comprises reacting the acid-ester recited hereinabove with a
source of sulfur and with a mercaptoalkanol of the formula
HS-(RO)nH (I)
wherein R is an alkylene group and n is a number ranging from
1 to about 20. The alkylene group usually contains from 2 to
about 24 carbon atoms, more often from 2 to about 8 carbon
atoms. Most often, R will contain 2 or 3 carbon atoms. The
number n preferably ranges from 1 to about 10, often from 1
to about 6. Very often, n equals 1.
Mercaptoalkanols are readily prepared by methods known
in the art. A preferred method is to react hydrogen sulfide
with an epoxide, such as ethylene oxide. Other useful
epoxides include alpha-olefin epoxides such as 1,2-epoxy
hexadecane and epoxides having the epoxy group at an internal
position, such as 9-10 epoxy butyl stearate. Other epoxides
useful for preparing mercaptoalkanols for use in the process
of this invention will occur to those skilled in the art.
The various reactants can be present in the process of
this reaction in amounts covering a broad range.
The amount of mercaptoalkanol of formula (I) used in the
process of this invention preferably ranges from about 0.5 to
about 2 moles, per mole of acid-ester. Preferably from about
0.9 to about 1.5 moles, more preferably from about 1 to about
1.2 moles of mercaptoalkanol per mole of acid-ester, are used
in the process of this invention.
As mentioned hereinabove, the amount of catalyst, if
employed in the process, depends on the particular nature
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of the catalyst and other reaction conditions, for
example, reaction temperature, nature of the various
reactants and the like.
The reactants preferably are employed within the
above-stated ranges. Generally, it is most desirable to
employ the reactants in amounts near the stoichiometric
amounts needed to prepare desired products. It is
sometimes helpful to use a moderate excess, for example,
about 5-10% excess, of one or more reactant. While it is
often possible to use a large excess of any of the various
reactants, the presence of excess reactant in the reaction
mixture or in the sulfur-containing polymeric polyester
usually does not provide any added benefit, and is thus
wasteful of raw materials. Also, when a large excess of
one or more reactants is employed, added cost is involved
if it is desired to remove any appreciable amount of
unreacted material.
The sulfurization reaction may be conducted at
temperatures ranging from about 40C to about 210C,
~0 preferably from about 80C to about 190C. The reaction
is most often conducted at atmospheric pressure, but may
be conducted under superatmospheric pressure, particularly
when one or more of the reactants is appreciably volatile
at the reaction temperature. Generally, there is no
advantage to conducting the reaction under reduced
pressure, except it is sometimes advantageous to remove
moderately volatile by-products under slightly reduced
pressure during the course of the reaction.
The polymeric polyester mav be recovered without
additional purification, that is, unreacted materials and
certain by-products may remain in the product. Generally,
by-products such as water of reaction, etc., are removed
during the course of the reaction, since the presence of
such by-products sometimes slows the progress of the
reaction. Volatile by-products are generally removed
during the course of reaction or thereafter by stripping,
often under reduced pressure, at elevated temperatures
2006~9
above the boiling point of the by-product, by nitrogen
blowing, and the like. Preferably, the polyester is purified
by stripping of remaining volatile by-products and unreacted
materials, filtration and the like after the reaction has
been completed. The sulfur-containing polyester preferably
has a molecular weight ranging from about 1000 to about
10000, more often from about 1000 to about 5000.
This invention also relates to sulfur-containing
polymeric polyesters comprising at least 2 repeating units of
the formula
O O
li ll
Ra(OR) m C ~ C - O(RO)~Ra
A Sx - A (II)
C / C (OR)nSx (RO) n -
O O
Often the polymeric polyester comprises from 2 to about 8
repeating units, frequently from about 3 to about 5 repeating
units. In formula II, each A is independently an alkylene
group containing from 2 to about 24 carbon atoms, more often
from 2 to about 4 carbon atoms. The A group may contain
substituents such as ester groups, carboxylic acid groups,
amide groups, and the like. Preferably, except for the
substituents shown in formula (II), A is free of
substituents. The carbonyl group containing substituents
shown in (II) are generally not on the same carbon atom of A.
Each Ra is independently H or an alkyl or aryl group,
preferably an alkyl group containing from 3 to about 30
carbon atoms, and more preferably an alkyl group containing
from 8 to about 24 carbon atoms. Each R is independently an
alkylene group, often containing from 2 to about 24 carbon
atoms. Preferably, each R independently contains from 2 to
about 4 carbon atoms. Each x is independently a number from
1 to about 6, and preferably, a number from 1 to about 3.
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Each m is independently 0 or a number from 1 to about 20,
preferably 0, and each n is independently a number ranging
from 1 to about 20, preferably from l to about 2.
The polymeric polyester comprising units of formula
(II) may terminate by linking with itself, forming a ring,
or each terminal group may independently comprise a group
of formula (III)
/ ~ O(RO)mRa
10 - A (III)
~C Z
wherein A is as defined hereinabove, each Z is
independently a member of the group consisting of - OH,
- NR1R2, - (OR)nS (RO)nH, or - O(R-O)mRa. Rl and R2 are
each independently H or lower alkyl groups (that is, alkyl
groups containing up to about 7 carbon atoms), each m is
independently zero or a number from 1 to about 20,
preferably zero or a number from 1 to about 2, each n is
independently a number from 1 to about 20, preferably from
1 to about 2, each y is zero or a numher from 1 to about
6, preferably zero or a number from 1 to about 3, and R
and Ra are as defined hereinabove, except thaf when y=0, R
is often a methylene or substituted methylene group; or,
when Z is -OH, that is when the terminal group contains a
carboxylic acid group, a salt may be formed by reaction
with a basic, metal-containing reagent, ammonia or an
amine. Preferred metals are sodium, magnesium, potassium,
calcium, zinc or copper. Examples of amines are
methylamine, butylamine, oleylamine, dibutylamine,
ethylene diamine and the like.
The polymeric polyester comprising units of formula
II frequently has a molecular weight ranging from about
1000 to ahout 10000, more often from about 1000 to about
5000. As is readily apparent, the number of repeating
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units and the number of carbon atoms and the nature of
substituent groups, if any, and terminal groups will
influence the molecular weight.
In yet another embodiment, a process is described for
preparing a sulfur-containing polymeric polyester which
comprises reacting sulfur-coupled acid-esters of
polycarboxylic acids with at least one member of a group
of thiodialkanols.
The Sulfur-Coupled Acid-Esters
The sulfur-coupled acid-esters of polycarboxylic
acids useful in this process have the general formula
(RcC)dR3-sx-R3(cRc)d (X)
wherein R3 is a hydrocarbon group, usually an aliphatic
hydrocarbon group. The R3 group often contains from 2 to
about 20 carbon atoms, preferably 2 to about 8 carbon
atoms, more preferably from 2 to about 4 carbon atoms.
The R3 group may be substituted by a hydrocarbon group
having from 1 to about 24 carbon atoms. The Rc group is
hydrogen, Ra(OR)m, wherein R, Ra and m are as defined
hereinabove, or hydrocarbyl, preferably alkyl, having from
about 3 to about 30 carbon atoms, often from about 4 to
about 24 carbon atoms, with the proviso that at least one
Rc in each (COORC)d group is H, wherein each (COORC)d
group contains an average of from 1 to about 1.3
carboxylic acid groups. The subscript d is independently
a number ranging from 2 to about 8, preferably 2 to about
3. Each x is independently a number from ~ to about 6,
preferably from 1 to about 3. In an especially preferred
embodiment, the sulfur coupled acid-ester comprises sulfur
coupled monoalkyl esters of dibasic acids, especially
those wherein the dibasic acid is a succinic acid.
Preferably, each ester moiety of the sulfur coupled
polycarboxylic acid contains, including the carbonyl
carbon, from about 4 to about 31 carbon atoms, preferably
20068~
- 18 -
from about 9 to about 25 carbon atoms, and more preferably up
to about 18 carbon atoms.
Many sulfur-coupled acid esters are known and can be
prepared by methods known to those skilled in the art. For
example, thio-bis-half esters of succinic acids can be
prepared by reacting hydrogen sulfide in the presence of a
basic catalyst with an acid-ester of maleic acid. Such a
process is described in U.S. 3,299,121. The sulfur-coupled
acid-ester may also be formed ln situ in a fashion analogous
to that described hereinabove for the acid-ester reactant.
The Thiodialkanols
Thiodialkanols useful in the process of this invention
are those having the formula
H(ORSXR)nOH , (IV)
the formula
H(OR)n~Sx~(RO)nH (V)
and the formula HO(RSx)nROH (XI)
and oligomers thereof, wherein x is a number from 1 to about
6, preferably from 1 to about 3, often 1, each R is
independently an alkylene group, which often contains from 2
to about 24 carbon atoms and preferably contains from 2 to
about 4 carbon atoms, each n is independently a number from
1 to about 20, preferably 1 to 5, more preferably from 1 to
about 2. It is, of course, recognized that when n=1, and all
of the other elements are the same the compounds represented
by formulae (IV), (V) and (XI) are the same.
The above-described thiodialkanols are known and may
be prepared by methods known to those skilled in the art.
For example, thiodialkanols of formula (V) can be prepared
X006859
-- 19 --
by condensing one mole of H2S with two-or more moles of an
epoxide. Mercaptoalkanols may be reacted with sulfur or
with various oxidizing agents to yield compounds of
formula (V). Specific details are familiar to those of
skill in the chemical arts. Useful epoxides include those
mentioned hereinabove in the description of mercapto-
alkanols and their preparation. Certain thiodialkanols of
formula (IV), also referred to in the art as thiodialkanol
polyethers, can be prepared by the condensation of thio-
dialkanols of formula (V) wherein n in formula (V) is 1.These materials are also available commercially from, for
example, Pennwalt or Morton-Thiokol, Inc. Thiodiakanols
of formulae (XI) can be prepared by condensation of
mercaptoalkanols with thiodalkanols.
Esterification catalysts, of the type, and in the
amounts, disclosed hereinabove may be used in the process
of reacting thiodialkanols with sulfur-coupled acid
esters. The reaction is usually conducted under such
conditions that water formed during the esterification is
removed continuously. A convenient method is to conduct
the reaction in a solvent, at reflux, and removing water
as an azeotrope. It is especially desirable to add the
mercaptoalkanol to a refluxing mixture of acid and
catalyst.
This invention also contemplates compositions
prepared by the processes of this invention, additive
concentrates comprising a substantially inert, normally
liquid diluent and about 1-90% by weight of the
compositions of this invention, and lubricating
compositions comprising a major amount of an oil of
lubricating viscosity, and a minor, property improving
amount of the compositions or additive concentrates of
this invention.
Also contemplated are lubricating oil compositions
comprising a major amount of an oil of lubricating
viscosity and minor amounts of polymeric polysuccinate
esters having at least 2 repeating units, often 2 to about
20068S9
- 20 -
8 repeating units, frequently from about 3 to about 5
repeating units of the formula
O O
¦ Q (VI).
Rb
Each Q is independently
n y n (VII)
or
(ORSyR)n (VIII).
Each R in the above formulas is independently an alkylene
group, preferably an alkylene group containing from 2 to
about 24 carbon atoms, more preferably from 2 to about 4
carbon atoms, and more often from 2 to 3 carbon atoms.
Each y is independently 0 or a number ranging from 1 to
about 6, more often a number ranging from 1 to about 3.
~ When y=0, each R is often a methylene or a substituted
methylene group. Each n is a number ranging from 1 to
about 20, more often a number ranging from l to about 5,
and preferably a number from 1 to about 2. Each Rb is
independently hydrocarbyl or hydrocarbylthio, preferably
alkyl or alkylthio, with the proviso that at least one Rb
is hydrocarbylthio. Preferably each Rb contains from 8 to
about 30 carbon atoms, more preferably from 8 to about 18
carbon atoms. Most preferably, each Rh is an alkylthio
group having from about 8 to about 30 carbon atoms, more
often from about 8 to about 24 carbon atoms, and usually
from about 8 to about 18 carbon atoms. The polysuccinate
ester of formula (VI) usually has a molecular weight
ranging from about 1,000 to about 10,000, more often from
about 1,000 to about 5,000.
2~068~9
- 21 -
Polymeric polysuccinate polyesters of formula (VI) can
be prepared by methods known in the art. For example, an
alkylthio-substituted succinic acid can be reacted with an
alpha-omega diol, a thiodialkanol and the like. Methods for
preparing various sulfur-containing polyesters falling within
the scope of formula VI are described in Stromberg (U.S.
patent 2,993,773). Other methods will occur to those of
ordinary skill in the art.
Methods for determining molecular weights of polymers
are well known in the art. Such methods include gel
permeation chromatography, boiling point elevation, vapor
phase osmometry and others. Textbooks on general polymer
chemistry, including "Macromolecules, An Introduction to
Polymer Science", F.A. Bovey and F.H. Winslow, Editors,
Academic Press, New York (1979), pages 296-316, and P.J.
Flory, "Principles of Polymer Chemistry", Cornell University
Press (1953) Chapter VII, pages 266-316, describe these
methods. It has been found that vapor phase osmometry (VPO)
is a particularly useful method for determining number
average molecular weights of the polysuccinate esters of this
invention.
Gel permeation chromatography is an effective tool for
measuring molecular weights, particularly when the instrument
is calibrated against known compounds of similar structure
and molecular weight.
The following examples are provided to illustrate the
processes and compositions of the present invention. These
examples are provided to teach those of ordinary skill in the
art how to make and use the compositions of this invention.
These illustrations are not to be interpreted as specific
limitations as to the scope of what the inventors regard as
their invention. Efforts have been made to insure accuracy
with respect to numbers used (e.g., amounts, temperature,
etc.). Unless indicated otherwise, parts are parts by
weight, temperature is in degrees Celsius and pressure is at
or near atmospheric.
2006859
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Example 1
A five-liter flask equipped with a nitrogen inlet, a
thermowell, a stirrer and a Dean-Stark trap is charged with
490 parts maleic anhydride, 1,080 parts of a mixture of
linear primary alcohols containing from about 12 to about 18
carbon atoms (Alfol* 12-18-Conoco), 1,000 parts toluene and
2.5 parts anhydrous sodium acetate. The mixture is heated
with stirring to 100C and held for 2 hours at 100C.
Infrared analysis indicates only a trace of anhydride
remaining. The materials are cooled to 45C followed by
addition of 160 parts sulfur and 7 parts magnesium oxide.
Mercaptoethanol, 390 parts, is added dropwise at 45C over
0.25 hours. No exothermic reaction is noted. The materials
are stirred 1 hour at 60C, 1 hour at 80C and 1 hour at
100C. The materials are then heated to reflux (140C) and
held at 140C for 6 hours. Solvent is removed by
distillation and reflux temperature increases to 180C. The
reaction is held at 180C for 5 hours while 79 parts water is
collected in the Dean-Stark trap. The reaction is stripped
to 160C at 20 Torr. The residue is filtered at 100C
through a diatomaceous earth filter aid. An oil-soluble
product is obtained containing 15.5~ sulfur and having a
number average molecular weight, determined by vapor phase
osmometry, of 1,796.
Example 2
Following essentially the same procedure described in
Example 1, a toluene solution (1,000 parts toluene) of 490
parts maleic anhydride, 1,080 parts Alfol 12-18 alcohol and
2.5 parts sodium acetate are reacted for 2 hours at 100C.
The reaction mixture is cooled to 45C and 7 parts magnesium
oxide and 80 parts sulfur are added. 390 parts
mercaptoethanol is added dropwise at 45C at 0.5 hours.
Heating is then conducted in the same fashion as described
*Trade-mark
2006~359
- 23 -
for Example 1. The reaction mixture is stripped to 160C
at 20 Torr, the residue is filtered through diatomaceous
earth filter aid yielding a product containing 11.8%
sulfur and having a number average molecular weight,
determined by vapor phase osmometry, of 1,650.
Example 3
The procedure of Example 1 is repeated except maleic
anhydride is replaced with an equivalent amount of
itaconic anhydride.
Example 4
The procedure of Example 1 is repeated replacing the
Alfol 12-18 alcohol with an equivalent amount (based on
OH) of isooctyl alcohol.
Example 5
The procedure of Example 1 is followed except a 10%
molar excess of mercaptoethanol is employed.
The following examples (Examples 6-8) illustrate
means for introducing various terminal functionality into
the polyesters of this invention. In these examples, the
polyester of Example 1 is post-treated with various
reagents in the amounts indicated.
Example Reagent Amount Functionality
6 Octyl alcohol 1 mole: Ester
equivalent acid
7 NaOH 1 equivalent: Salt
1 equivalent acid
Dibutylamine 1 mole:mole acid Salt
Z0~68S9
- 24 -
Example 9
A sulfur-containing polyester is prepared by reacting
770 parts 2,2'-thio bis(oleyl hydrogen succinate) with 162
parts of 95~ purity 2-hydroxyethyl disulfide.
5Example 10
Following the procedure of Example 9, 350 parts
2,2'-thio bis(ethyl hydrogen succinate) are reacted with
162 parts of 95% 2-hydroxyethyl disulfide.
Example 11
10Example 9 is repeated replacing 2-hydroxyethyl
disulfide with 122 parts 2-hydroxyethyl sulfide.
Example 12
Example 9 is repeated replacing 2-hydroxyethyl
disulfide with 434 parts of a thiodiglycol polyether
having the average composition
H(OCH2CH2SCH2CH2)40H.
Example 13
A polymeric polysuccinate ester is prepared by
reacting 1 mole of 2-octadecyl-thio succinic anhydride
with 1 mole of 2-hydroxyethyl disulfide.
Example 14
Example 13 is repeated replacing 2-hydroxyethyl
disulfide with 1 mole 2-hydroxyethyl sulfide.
Example 15
25Example 13 is repeated replacing 2-hydroxyethyl
disulfide with 522 parts of the thiodiglycol polyether
described in Example 12.
Lubricating compositions of this invention may be
prepared by adding the sulfur-containing polyesters
directly into the base oil. More often, the compositions
20068S9
- 25 -
of this invention are present as components of an additive
concentrate which may contain other additives and which
often contains an inert organic diluent. Such additive
concentrates usually comprise from about 1 to about 90~ by
weight of the polyesters of this invention.
The polymeric sulfur-containing polyesters described
herein are used in oils of lubricating viscosity at levels
adequate to provide enhanced performance benefits to the
lubricating composition. They are present in minor
amounts in lubricating compositions comprising a major
amount of an oil of lubricating viscosity. By minor
amounts is meant less than 50% of the total, e.g., 1%, 5%,
49~, etc. Major amounts are greater than 50~ of the
total, e.g., 50.5%, 70~, 99~, etc. The polymeric
polyesters of this invention are frequently used at levels
ranging from about 0.05 to about 35 percent by weight of
the lubricating composition. More often they constitute
at least 0.1~ up to about 20%, more often up to about 5~
by weight. In phosphorus-free hydraulic fluids they are
frequently used at from about 0.1-3% by weight of the
total composition, often from about 0.25 to about 1% by
weight, and more often from about 0.5 to about 0.75% by
weight.
The lubricating compositions of this invention employ
an oil of lubricating viscosity, including natural or
synthetic lubricating oils or mixtures thereof.
Natural oils include animal oils and vegetable oils
(e.g. castor oil, lard oil) as well as mineral lubricating
oils such as liquid petroleum oils and solvent-treated or
acid-treated mineral lubricating oils of the paraffinic,
naphthenic or mixed paraffinic-naphthenic types. Oils of
lubricating viscosity derived from coal or shale are also
useful. Synthetic lubricating oils include hydrocarbon
oils and halosubstituted hydrocarbon oils such as polymer-
ized and interpolymerized olefins, etc. and mixturesthereof, alkylbenzenes, polyphenyls (e.g., biphenyls,
terphenyls, alkylated polyphenyls, etc.), alkylated
2006859
- 26 -
diphenyl ethers and alkylated diphenyl sulfides and the
derivatives, analogs and homologs thereof and the like.
Alkylene oxide polymers and interpolymers and
derivatives thereof where the terminal hydroxyl groups have
been modified by esterification, etherification, etc.,
constitute another class of known synthetic lubricating oils
that can be used.
Another suitable class of synthetic lubricating oils
that can be used comprises the esters of dicarboxylic acids
with a variety of mono- and polyhydric alcohols or polyol
ethers, and those made from Cs to C12 monocarboxylic acids and
polyols and polyol ethers.
Other synthetic lubricating oils include liquid esters
of phosphorus-containing acids, polymeric tetrahydrofurans
and the like, silicon-based oils such as the polyalkyl-,
polyaryl-, polyalkoxy-, or polyaryloxy-siloxane oils and
silicate oils.
Unrefined, refined and rerefined oils, either natural or
synthetic (as well as mixtures of two or more of any of
these) of the type disclosed hereinabove can be used in the
lubricating compositions of the present invention. Unrefined
oils are those obtained directly from a natural or synthetic
source without further purification treatment. Refined oils
are similar to the unrefined oils except they have been
treated in one or more purification steps to improve one or
more properties. Rerefined oils are obtained by processes
similar to those used to obtain refined oils applied to
refined oils which have been already used in service. Such
rerefined oils often are additionally processed by techniques
directed to removal of spent additives and oil breakdown
products.
Specific examples of the above-described oils of
lubricating viscosity are given in Chamberlin III, U.S.
4,326,972 and European Patent Publication 107,282.
200685~
- 27 -
A basic, brief description of lubricant base oils
appears in an article by D.V. Brock, "Lubrication
Engineering", Volume 43, pages 184-5, March, 1987.
Other Additives
As mentioned, the compositions, additive concentrates
and lubricating compositions of this invention may contain
other additives. The use of such additives is optional, and
the presence thereof in the compositions, additive
concentrates and lubricating compositions of this invention
will depend on the particular use and level of performance
required. One optional additive is a metal salt of a
dithiophosphoric acid. Examples include copper, molybdenum,
nickel and zinc salts of dithiophosphoric acids. Salts of
dithiophosphoric acids are often referred to as metal
dithiophosphates, metal O,O-dihydrocarbyl dithiophosphates,
and by other commonly used names. The zinc salts are
sometimes referred to by the abbreviation ZDP. One or more
metal salts of dithiophosphoric acids may be present in a
minor amount to provide additional extreme pressure, anti-
wear and anti-oxidancy properties. Of course, in low-
phosphorus containing compositions, the amount of salt of
dithiophosphate will be limited and will not be present at
all in phosphorus-free compositions.
In addition to metal salts of dithiophosphoric acids
discussed hereinabove, other additives that may optionally be
used in the compositions, additive concentrates and
lubricating compositions of this invention include, for
example, detergents, dispersants, viscosity improvers,
oxidation inhibiting agents, pour point depressing agents,
extreme pressure agents, anti-wear agents, color stabilizers,
anti-foam agents, and anti-oxidants.
Auxiliary extreme pressure agents and corrosion and
oxidation inhibiting agents are exemplified by chlorinated
aliphatic hydrocarbons, organic sulfides and polysulfides,
2006859
- 28 -
phosphorus esters including dihydrocarbon and trihydrocarbon
phosphites, molybdenum compounds, and the like.
Viscosity improvers (also sometimes referred to as
viscosity index improvers) are usually polymers, including
polyisobutenes, polymethacrylic acid esters, diene polymers,
polyalkyl styrenes, alkenylarene-conjugated diene copolymers
and polyolefins. Multifunctional viscosity improvers which
also have dispersant and/or anti-oxidancy properties are
known and may optionally be used.
Pour point depressants are a particularly useful type of
additive. See for example, page 8 of "Lubricant Additives"
by C.V. Smalheer and R. Kennedy Smith (Lezius-Hiles Company
Publishers, Cleveland, Ohio, 1967). Pour point depressants
useful for the purpose of this invention, techniques for
their preparation and their use are described in U.S. Patent
numbers 2,387,501; 2,015,748; 2,655,479; 1,815,022;
2,191,498; 2,666,748; 2,721,877; 2,721,878; and 3,250,715.
Anti-foam agents used to reduce or prevent the formation
of stable foam include silicones or organic polymers.
Examples of these and additional anti-foam compositions are
described in "Foam Control Agents", by Henry T. Kerner (Noyes
Data Corporation, 1976), pages 125-162.
Detergents and dispersants may be of the ash-producing
or ashless type. The ash-producing detergents are
exemplified by oil soluble neutral and basic salts of alkali
or alkaline earth metals with sulfonic acids, carboxylic
acids, phenols or organic phosphorus acids characterized by
at least one direct carbon-to-phosphorus linkage.
The term ~basic salt~ is used to designate metal
salts wherein the metal is present in stoichiometrically
larger amounts than the organic acid radical. Basic salts
and techniques for preparing and using them are well known
~ .
2006~3S9
- 29 -
to those skilled in the art and need not be discussed in
detail here.
Ashless detergents and dispersants are so-called
despite the fact that, dependinq on its constitution, the
detergent or dispersant may upon combustion yield a
non-volatile residue such as boric oxide or phosphorus
pentoxide; however, it does not ordinarily contain metal
and therefore does not yield a metal-containing ash on
combustion. Many types are known in the art, and any of
them are suitable for use in the lubricants of this
invention. The following are illustrative:
(1) Reaction products of carboxylic acids (or
derivatives thereof) containing at least about 34 and
preferably at least about 54 carbon atoms with nitrogen
containing compounds such as amine, organic hydroxy
compounds such as phenols and alcohols, and/or basic
inorganic materials. Examples of these "carboxylic
dispersants" are described in British Patent number
1,306,529 and in many U.S. patents including the
following:
3,163,603 3,381,022 3,542,680
3,184,474 3,399,141 3,567,637
3,215,707 3,415,750 3,574,101
3,219,666 3,433,744 3,576,743
3,271,310 3,444,170 3,630,904
3,272,746 3,448,048 3,632,510
3,281,357 3,448,049 3,632,511
3,306,908 3,451,933 3,697,428
3,311,558 3,454,607 3,725,441
3,316,177 3,467,668 4,]94,886
3,340,281 3,501,405 4,234,435
3,341,542 3,522,179 4,491,527
3,346,493 3,541,012 RE 26,433
3,351,552 3,541,678
2006859
- 30 -
(2) Reaction products of relatively high molecular
weight aliphatic or alicyclic halides with amines, prefer-
ably polyalkylene polyamines. These may be characterized
as "amine dispersants" and examples thereof are described
for example, in the following U.S. patents:
3,275,554 3,454,555
3,438,757 3,565,804
(3) Reaction products of alkyl phenols in which the
alkyl groups contains at least about 30 carbon atoms with
aldehydes (especially formaldehyde) and amines (especially
polyalkylene polyamines), which may be characterized as
"Mannich dispersants". The materials described in the
following U.S. patents are illustrative:
3,413,347 3,725,480
3,697,574 3,726,882
3,725,277
(4) Products obtained by post-treating the
carboxylic amine or Mannich dispersants with such reagents
as urea, thiourea, carbon disulfide, aldehydes, ketones,
carboxylic acids, hydrocarbon-substituted succinic
anhydrides, nitriles, epoxides, boron compounds, phospho-
rus compounds or the like. Exemplary materials of this
kind are described in the following U.S. patents:
Z006859
3,036,003 3,282,955 3,493,520 3,639,242
3,087,936 3,312,619 3,502,677 3,649,229
3,200,107 3,366,569 3,513,093 3,649,659
3,216,936 3,367,943 3,533,945 3,658,836
3,254,025 3,373,111 3,539,633 3,697,574
3,256,185 3,403,102 3,573,010 3,702,757
3,278,550 3,442,808 3,579,450 3,703,536
3,280,234 3,455,831 3,591,598 3,704,308
3,281,428 3,455,832 3,600,372 3,708,522
4,234,435
(5) Interpolymers of oil-solubilizing monomers such
as decyl methacrylate, vinyl decyl ether and high molecu-
lar weight olefins with monomers containing polar
substituents, e.g., aminoalkyl acrylates or methacrylates,
acrylamides and poly-(oxyethylene)-substituted acrylates.
These may be characterized as "polymeric dispersants" and
examples thereof are disclosed in the following U.S.
patents:
3,329,658 3,666,730
3,449,250 3,687,849
3,519,565 3,702,300
The above-noted patents are incorporated by reference
herein for their disclosures of ashless dispersants.
The above-illustrated additives may each be present
in lubricating compositions at a concentration of as
little as 0.001% by weight usually ranging from about
0.01% to about 20% by weight. In most instances, they
each present at from about 0.1% to about 10% b~ weight.
The various additives and compositions described
herein can be added directly to the lubricating oil.
Preferably, however, they are diluted with a substantially
inert, normally liquid organic diluent such as mineral
oil, naphtha, benzene, toluene or xylene, to form an
2006859
- 32 -
additive concentrate. These additive concentrates usually
comprise about 1 to about 90~ by weight of the composi-
tions of this invention and may contain, in addition, one
or more other additives known in the art or described
hereinabove. Chemical concentrations such as 15%, 20~,
30% or 50% or higher may be employed.
The lubricating compositions of this invention find
utility in many areas. Examples include, but are not
limited to, lubricants for internal combustion engines,
such as fuel economy improving oils, power transmission
fluids such as automatic transmission fluids, hydraulic
fluids, power shift oils and tractor oils. Tractor oils
frequently serve multiple purposes such as hydraulic
fluids, wet brake lubricants, engine lubricants, etc., all
employing a lubricant from a common sump. Other areas of
application include industrial applications such as
metal-working fluids and industrial gear oils. The
compositions of this invention also find utility in
various aqueous systems such as are described by Forsberg
in U.S. 4,329,429, U.S. 4,368,133, U.S. 4,448,703, and in
other aqueous compositions, as extreme pressure/antiwear
additives.
The hereindescribed sulfur-containing polyesters
enhance the performance of oils of lubricating viscosity.
They provide extreme pressure and antiwear properties to
gear lubricants, both automotive and industrial gear oils.
They serve as non-phosphorus extreme pressure/antiwear
additives for hydraulic fluids. In tractor lubricants
they provide extreme pressure, antiwear, and, particularly
when the polyester contains hydrocarbon groups containing
from about 8 to about 24 carbon atoms, anti-chatter
performance for wet brakes. The sulfur-containing
polyesters also provide wear protection for engine oils,
and are particularly beneficial for low-phosphorus
containing engine oils. Low phosphorus engine oils are
those containing less than about 0.08~ by weight of
phosphorus, preferably less than about 0.05% by weight of
200~859
- 33 -
phosphorus. Particularly valuable are compositions that
are essentially free of phosphorus. They are also useful
in power transmitting fluids such as automatic
transmission fluids and hydraulic fluids which require a
balance of anti-oxidancy, anti-wear, friction modification
and other properties. It has been found that the
polymeric polyesters of this invention can be used as
additives for hydraulic fluids that are essentially free
of phosphorus. Such fluids are especially desirable and
valuable. The sulfur-containing polyesters of this
invention also impart antioxidancy to organic systems,
e.g., lubricants.
Typical additive concentrates and lubricating oil
compositions of this invention are illustrated by the
following Examples. The lubricating compositions are
prepared by combining the specified ingredients in the
indicated amounts, individually or from concentrates, and
oil of lubricating viscosity to make the total 100 parts
by weight. The amounts shown are parts by weight and,
unless indicated otherwise, are amounts of chemical
present on an oil-free basis. Thus, for example, an
additive comprising 50% oil used at 10% by weight in a
blend, provides 5% by weight of chemical. Any oil which
may be present in a listed additive is considered, for the
purposes of these Examples, to be part of the oil of
lubricating viscosity. Unless otherwise indicated, listed
amounts of purchased commercial additives are not adjusted
for oil content. These examples are presented for
illustrative purposes only, and are not intended to limit
the scope of this invention.
Examples A-B
Engine Oils
Two lubricating compositions are prepared by blending
into a mineral oil basestock (Exxon stocks), 0.52 parts of
hydrogenated styrene-diene copolymer, 0.08 parts of amine
2oo~85g
neutralized styrene-alkyl maleate copolymer, 1.65 parts of
polyisobutenyl substituted succinimide, 0.23 parts of zinc
dialkyl dithiophosphate, 0.10 parts of fatty acid amide, 0.25
parts of calcium overbased sulfonate, 0.42 parts of a
commercial magnesium sulfonate (Witco), 1.0 part of the
product of Example 1, 50 parts per million (ppm) of a 10
solution in kerosene of silicone antifoam and additional
amounts of other additives as indicated hereinbelow:
Additional Ingredient Example
A B
SAE Grade lOW-30 lOW-40
Alkylated aryl amine 0.25 0.34
Sulfurized Diels-Alder adduct 1.80 2.20
Copper salt of organic acid 0.05
Sodium overbased sulfonate 0.21 0.30
Example C
Tractor Fluids
A composition intended for use as a multi-purpose
lubricant, serving as an engine oil and gear lubricant, a
hydraulic fluid and a wet-brake lubricant, all from a single
sump on a tractor, which composition comprises a mineral oil
basestock (Amoco* lOW-30), 3.0 parts of a commercial
methacrylate copolymer (Acryloid* 953 - Rohm & Haas), 0.15
parts of a commercial pour point depressant (Hitec* E-672 -
Ethyl), about 0.02 parts of a mixture of hydrocarbonsolutions of silicone antifoam agents, 1.1 parts of the
reaction product of polyisobutenyl substituted succinic
anhydride with pentaerythritol and a polyamine, 0.94 parts
of a polyisobutenyl substituted succinimide, 1.86 parts
of calcium overbased sulfurized alkyl phenol, 3.90
parts of a mixture of zinc salts of dialkyl-
dithiophosphates, 1.62 parts of a mixture of basic
magnesium sulfonates, including 0.50 parts of a commercial
*Trade-marks
2006859
- 35 -
product sold as Hybase M400 (Witco) and 2.0 parts of the
product of Example 1.
Example D-F
Hydraulic Fluid Compositions
Example
Component D E F G
Mineral oil (Sun 250 Neutral) Balance ~-
Expoxide post-treated dialkyl 0.60
dithiophosphate-alkyl acrylate
reaction product
Alkyl aromatic triazole 0.005 0.001 0.01
Alkyl aromatic amine 0.42 0.420.25
Partial hydroxy alkyl ester of0.03 0.030.05
alkyl substituted succinic acid
Commercial polyoxyalkylene 0.007 0.007 0.008
demulsifier (Petrolite)
Product of Example 1 0.20 2.4 0.15 0.6
Zinc salt of dialkyl 0.47
dithiophosphate-carboxylic
20 acid mixture
Basic calcium sulfonate 0.01
Alkyl phenol 0.18 0.25
Commercial basic calcium 0.07
sulfurized phenate (Oloa* 219 -
25 Chevron)
Examples H-J
Gear Lubricants
Example H
A lubricating composition is prepared by blending into
an SAE 80W-90 basestock (Exxon), 0.40 parts of an amine
modified styrene-alkyl maleate copolymer and 2.0 parts of the
product of Example 2.
*Trade-mark
200~8S9
- 36 -
Example I
A lubricating composition like that of Example G is
prepared except it also contains 0.22 parts of a zinc salt
of a dialkyldithiophosphate.
Example J
A lubricating composition is prepared by blending
into an SAE 80W-90 basestock (Exxon), 0.40 parts of an
amine modified styrene-alkyl maleate copolymer, 4.5 parts
of the product of Example 1, 1.35 parts of an amine salt
of a mixed mono- and di-alkyl phosphate, 0.35 parts of a
fatty amine, 0.1 parts of a dimercaptothiadiazole based
corrosion inhibitor (Amoco 153 - Amoco) and 0.1% of a
mixed ester antifoam agent.
Examples K-N
Automatic Transmission Fluids
Example K
A composition is prepared by blending into a mineral
oil base (100 neutral oil - Cities) 0.025 parts of red
dye, 0.042 parts of a kerosene solution of silicone
antifoams, 1.16 parts of a carbon disulfide post-treated
polyisobutene substituted succinimide, 0.67 parts of a
borated polyisobutene substituted succinimide, 0.125 parts
of ethoxylated fatty amine, 0.16 parts of a fatty
hydroxylalkyl imidazoline, 0.53 parts of basic calcium
sulfonate, 0.01 parts of alkyl aromatic triazole, 0.03
parts of a zinc salt of a dialkyl dithiophosphate, 0.10
parts of alkylated aryl amine, 0.593 parts of hydroxy
thioether, 1.57 parts of amine modified styrene-alkyl
maleate copolymer, and 0.50 parts of the product of
Example 1.
Example L
A composition like that of Example J is prepared,
except it also contains 0.11 parts of dibutyl phosphite.
20~5~
Example M
A composition is preparéd by blending into a mineral oil
base (100 neutral - Cities), 0.025 parts of red dye, 1.79
parts of an amine-modified styrene-alkyl maleate copolymer,
0.028 parts of a kerosene solution of silicone antifoams,
1.75 parts of a polyisobutenyl substituted succinimide, 0.68
parts of a borated polyisobutenyl substituted succinimide,
0.31 parts of basic calcium sulfonate, 0.50 parts of a zinc
salt of dialkyl dithiophosphates, 0.194 parts of the reaction
product of tetrapropenyl substituted succinic anhydride with
a commercially available polyoxyethylene glycol (Carbowax*
300 - Union Carbide), 0.613 parts of a hydroxythioether, 0.09
parts of alkylated aryl amine and 0.70 parts of the product
of Example 2.
Example N
A composition is prepared by blending with a mineral oil
basestock (Exxon ATF base) 0.025 parts of red dye, 0.042
parts of a kerosene solution of silicone antifoams, 1.14
parts of a carbon disulfide, post-treated polyisobutene
substituted succinimide, 0.66 parts of a borated
polyisobutene substituted succinimide, 0.53 parts of basic
calcium sulfonate, 0.09 parts of ethoxylated fatty amine,
0.015 parts of alkyl aromatic triazole, 0.08 parts of alkyl
aromatic amine, 0.57 parts of a hydroxythioether, 0.15 parts
of the product of Example 2 and 1.40 parts of an amine
modified styrene-alkyl maleate copolymer.
As mentioned hereinabove, one advantage of the
sulfur-containing polyesters of this invention is their
ability to impart wear protective properties to lubricating
oil compositions. It is desirable that the improvement
in wear protection is not made at the expense of
other desirable properties of a lubricating oil
composition. Wear protection can be measured by a number
of tests, including the Ford Sequence V-D test. This
*Trade-mark
20068~9
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well-known test is described in the "CRC Handbook of
Lubrication", Vol. 1, E. Richard Booser, Ed., CRC Press
Inc. (1983). It is an eight-day test conducted in 4-hour
cycles simulating both turnpike and city driving
conditions. Test parameters that are closely controlled
include oil, coolant, and inlet air temperatures, coolant
flow rate, air-fuel ratio, blowby rate, speed and load.
The engine is equipped with a heat exchanger in the blowby
system which acts both as a blowby condenser and a
reaction chamber to accelerate oil deterioration.
At the test conclusion, the engine is inspected for
sludge and varnish deposits using standard rating
techniques. Wear measurements are made of the camshaft
lobes and piston rings. Weight losses of the cam
followers and connecting rod bearing inserts are also
determined.
The lubricating composition of Example A was
subjected to the Ford Sequence V-D test with the following
results:
Engine Sludge (10 = Clean) : 9.55
Engine Varnish (10 = Clean) : 6.92
Camshaft Lobe Wear : Maximum 1.6
(Mils (thousandths of an inch)) Average 0.95
A modified Ford Sequence V-D test wherein the test
duration is reduced to 96 hours, and the other test
parameters are essentially the same as for the full V-D
test, was used to evaluate the performance of the
lubricating composition of Example B with the following
results:
Camshaft Lobe Wear - Maximum 0.90
(Mils (thousandths of an inch)) Average 0.76
20068S9
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It has been suprisingly found that essentially
phosphorus-free hydraulic 1uids comprising additives of
this invention will pass wear tests which previously have
required the presence of phosphorus, usually as a zinc
salt of a dithiophosphoric acid in the hydraulic fluid
employed therein.
